The two performers were joined by a huge choir on stage at the Dolby Theatre in Hollywood as they performed the song from the Selma soundtrack.

As the camera panned from the artists to the crowd mid-performance, Selma star David Oyelowo had tears streaming down his face.

(Image: Reuters)

And it wasn't just British actor David who was crying - TV star Oprah Winfrey, Chris Pine and Jessica Chastain were also in tears by the end of the performance, which was also met with a standing ovation.

Selma - the acclaimed film about civil rights campaigner Dr. Martin Luther King - was widely thought to be snubbed after it only received two nominations.

Just minutes later, the track scooped Best Song, beating Everything Is Awesome from The Lego Movie, Grateful from Beyond The Lights, I'm Not Gonna Miss You and Lost Stars from Begin Again.

Accepting the award, Legend gave an impassioned speech, telling the crowd: "We know that right now, the fight for freedom and justice is real."

Fellow performer Jennifer Hudson later wrote on Twitter about her fellow performers: "So proud n happy for you yes! Yes! N yes! Such a powerful moment. So proud to witness [sic]."